bitcoin-scripts

Using your favorite programming language solves the following

Exercise 1: Build and Validate a P2PKH Script

Goal: Understand basic Bitcoin Script by constructing and validating a Pay-to-Public-Key-Hash (P2PKH) transaction output.

Steps:

1. Generate a private key and derive its public key and hash:

   • Generate a private key.
   • Derive the public key from the private key.
   • Compute the public key hash (e.g., RIPEMD-160(SHA-256(pubkey))).

2. Construct a P2PKH locking script:

   • OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG

3. Simulate an unlocking script with a dummy signature and public key.

4. Write a function to “execute” the script:

   • Push unlocking script items onto a stack.
   • Apply locking script opcodes (duplicate, hash, compare, check signature).
   • Return True if valid, False otherwise.

Exercise 2: Simulate a 2-of-3 Multisig Transaction

Goal: Explore multi-signature setups by creating and spending a multisig output.

Steps:

1. Generate 3 keypairs (private/public keys).

2. Build a 2-of-3 multisig locking script:

   • OP_2 <pubKey1> <pubKey2> <pubKey3> OP_3 OP_CHECKMULTISIG

3. Simulate spending with 2 signatures from any 2 keys.

4. Write a function to validate the multisig script execution.